Turbo Questions
#1
Turbo Questions
I recently noticed on my 1994 Chevy 6.5Liter I am losing power, I have a good feeling that the turbo is not working properly (waste-gate seems to not be opening or closing all the time) I started to check into the turbo looking for things that might be loose or vacuum that was broke or disconnected, Vacuum line was fine to the waste gate and I also checked the hg's coming out of the vacuum pump. It is reading 25" hg's roughly. Next I noticed the arm linkage for the waste gate accuater was seized up and kind of hard to move, I fixed that was some WD40. Turbo stills doesn't seem to be building to much boost not closing or opening the waste gate. I have no idea I don't know much about turbos. Let me know what I should try.
#6
#7
On a non wastegated turbo it's a simple relationship between fuel and turbine speed.
On a wastegated turbo (IE: GMx turbos) turbine speed is regulated by wastegate action. Be it either by spring, boost referenced, drive pressure referenced or electronic control.
Chuck as much fuel at a wastegated turbo as you want, it's not going to accelerate if the wastegate is open or leaking (which I would suspect in this case given the OP comments about a stuck wastegate and wd40).
If the wastegate solenoid, wastgate vacuum pot of the wastegate itself aren't working properly, you're not going to get the boost levels the PCM is allowing for based on fuel scheduling.
However, assuming all this doesn't matter (which it does), if you're being so limited on fuel that you can't build drive pressure in the turbo, you're going to have lots of other more serious symptoms and indications on a 6.5 besides "I think the power is down" or "the turbo ain't working' right".....
Last edited by great white; 05-02-2012 at 02:21 PM. Reason: Automerged Doublepost
#8
And FYI, it applies the same to wastegated and VGT turbos too. If you lack fuel, you won't be able to spool up any turbo correctly.
On a VGT its even more noticeable from the vanes not moving as actively as normal (staying closed longer trying reach the desired boost pressure with high drive pressure instead of exhaust volume).
On a wastegated turbo (IE: GMx turbos) turbine speed is regulated by wastegate action.
if you're being so limited on fuel that you can't build drive pressure in the turbo, you're going to have lots of other more serious symptoms and indications on a 6.5 besides "I think the power is down" or "the turbo ain't working' right"
Last edited by Whargoul; 05-06-2012 at 09:43 AM.
#9
The 6.5 does not use a non-wastegated turbo.
And FYI, it applies the same to wastegated and VGT turbos too. If you lack fuel, you won't be able to spool up any turbo correctly.
On a VGT its even more noticeable from the vanes not moving as actively as normal (staying closed longer trying reach the desired boost pressure with high drive pressure instead of exhaust volume).
Sorry, that is only HALF true. Wastegated turbos work exactly the same as non-wastegated turbos, the only difference is exhaust velocity at the turbine exducer.
Wrong. A plugged fuel filter will simply cause a reduction in power, unless it is ignored long enough to completely clog and then it can cause hard starting too.
And FYI, it applies the same to wastegated and VGT turbos too. If you lack fuel, you won't be able to spool up any turbo correctly.
On a VGT its even more noticeable from the vanes not moving as actively as normal (staying closed longer trying reach the desired boost pressure with high drive pressure instead of exhaust volume).
Sorry, that is only HALF true. Wastegated turbos work exactly the same as non-wastegated turbos, the only difference is exhaust velocity at the turbine exducer.
Wrong. A plugged fuel filter will simply cause a reduction in power, unless it is ignored long enough to completely clog and then it can cause hard starting too.
Welcome to the ignore list.
You may now commence your rant about how much you know and how childish you think I am. I have no tolerance for it anymore...
Last edited by great white; 05-06-2012 at 10:49 AM.
#10